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Abstract:

The invention refers to a process to produce H2 from biomass
containing carbon. The biomass is gasified to obtain a gaseous flow
essentially containing molecules of carbon monoxide (CO) and molecules of
molecular hydrogen (H2). These molecules (CO) and (H2) are then
oxidized by oxygen holders in oxidized state (MeO) to obtain a gaseous
flow essentially containing CO2 and water steam (H2Osteam)
and oxygen holders in reduced state (Me). The oxygen holders are then
oxidized by water steam. That oxidation produces oxidized oxygen holders
and a gaseous flow essentially containing di-hydrogen (H2). The
invention also refers to a system containing the means to perform the
steps of such a process.

Claims:

1. A process to produce hydrogen (H2) from dry carbonated raw
material (MPCS), said process characterized by comprising at least one
iteration of the following steps: gasification in a first so-called
gasification reactor of carbonated raw material (MPCS) with a gaseous
flow of gasification (FGG) essentially comprising CO2 at high
temperature and oxygen (O2), said gasification supplying a first
gaseous flow (PFG) essentially comprising molecules of carbon monoxide
(CO) and eventually molecules of H2; oxidation in second so-called
oxidation reactor by oxygen holders in oxidized state (MeO) and a flow of
oxygen, being said molecules of carbon monoxide (CO) and molecular
hydrogen (H2) present in said first gaseous flow (PFG), said
oxidation supplying a second gaseous flow (DFG) at high temperature
containing CO2, oxygen holders in reduced state (Me) and an excess
of thermal power; activation in a third so-called activation reactor
(106) of said oxygen holders in reduced state (Me) by a gaseous flow of
activation (FA) essentially comprising water steam (H2Osteam)
at high temperature, said activation supplying oxygen holders in oxidized
state (MeO), a third gaseous flow (FGH) comprising hydrogen (H2) and
an excess of thermal power.

2. The process of claim 1, further comprising, on one hand, the use of
the thermal power of said second gaseous flow (DFG) and/or said thermal
excess of said oxidation/activation for the production of at least a part
of said gaseous flow of activation (FA) from water.

3. The process of claim 1, further comprising the recovery of at least a
part (TFG1) of the CO2 present in the second gaseous flow (DFG) to
constitute at least a part of the gaseous flow of gasification (FGG) for
the following cycle.

4. The process of claim 1, further comprising the recovery of at least a
part of the water steam (H2Osteam) eventually present in the
second gaseous flow (DFG) to constitute at least a part of the gaseous
flow of activation (FA).

5. The process of claim 1, further comprising, on the other hand, an
increase in temperature of the gaseous flow of gasification (FGG) with at
least a part of the thermal excess of oxidation of the first gaseous flow
(PFG) by oxygen holders and activation of said oxygen holders and a part
of the thermal power as generated during the gasification to bring said
gaseous flow of gasification (FGG) to the gasification temperature for
the next cycle.

6. The process of claim 1, further comprising, on the other hand,
recycling by photosynthesis of a part (TFG2) of the CO2 present
in the second gaseous flow (DFG) in a microalga culture bioreactor, said
bioreactor supplying, on one hand, a gaseous flow of oxygen (FO2)
and, on the other hand, carbonated biomass (BC).

7. The process of claim 6, further comprising the use of at least a part
of the gaseous flow of oxygen (FO2) in the gasification reactor to
gasify the carbonated raw material (MPCS).

8. The process of claim 6, further comprising the recovery of at least a
part of the carbonated biomass (BC) for gasification in the gasification
reactor.

9. A system to produce hydrogen (H2) from dry carbonated raw
material (MPCS), said system comprising: a gasification reactor for
carbonated raw material (MPCS) with a gaseous flow of gasification (FGG)
essentially comprising CO2 at high temperature and oxygen (O2);
said gasification reactor supplying a first gaseous flow (PFG) at high
temperature essentially containing molecules of carbon monoxide (CO) and
eventually molecules of H2; a reactor for oxidation by oxygen
holders in oxidized state (MeO) of said molecules of carbon monoxide (CO)
and molecular hydrogen (H2) as present in said first gaseous flow
(PFG), said oxidation reactor (104) supplying a second gaseous flow (DFG)
at high temperature containing CO2, oxygen holders in reduced state
(Me) and an excess of thermal power; an activation reactor of said oxygen
holders in reduced state (Me) by a gaseous flow of activation (FA)
essentially containing water steam (H2Osteam) at high
temperature, said activation reactor supplying oxygen holders in oxidized
state (MeO), a third gaseous flow (FGH) at room temperature comprising
hydrogen (H2) and an excess of thermal power.

10. The system of claim 9, further comprising, on the other hand, a
thermal exchanger supplying at least a part of said gaseous flow of
activation (FA) from water and at least a part of the thermal power of
said second gaseous flow (DFG) and/or said thermal excess of said
activation.

11. The system of claim 9, further comprising a recycling circuit of at
least a part (TFG1) of the CO2 present in the second gaseous flow
(DFG) to constitute at least a part of the gaseous flow of gasification
(FGG) for the next cycle.

12. The system of claim 9, further comprising another microalga culture
bioreactor for recycling by photosynthesis of a part (TFG2) of the
CO2 present in the second gaseous flow (DFG), with said bioreactor
supplying, on one hand, a gaseous flow of oxygen (FO2) and, on the
other hand, carbonated biomass (BC).

13. The system of claim 12, further comprising: a recovery circuit for at
least a part of the gaseous flow of oxygen (FO2) for injection in
the gasification reactor to gasify the carbonated raw material containing
carbon (MPCS); and/or a recovery circuit for at least a part of the
carbonated biomass (BC) for gasification in the gasification reactor.

Description:

[0001] The invention refers to a process for the production of hydrogen.
It also refers to a system to put that procedure into practice.

[0002] The scope of the invention is the scope of generation of hydrogen
from a raw material containing carbon and water steam.

[0003] The production of hydrogen by reforming water steam over a raw
material containing carbon is perfectly known and coded by the different
producers in the industry and is called steam reforming.

[0004] The most widely used steam reforming is currently methane steam
reforming: CH4+2H2O→CO2+4 H2. These reactions
consume thermal power and reject fatal CO2 (coming from the
materials containing fossil carbons). They are produced in multiple
stages at 800/900° C. and at pressures of 3.0/3.5 MPa over
catalysts. Thermochemical reactions produced during steam reforming are
globally endothermal (165 kJ/mole of CH4) and the heating power of
one mole of CH4 is 804 kJ/mole.

[0005] The most widely used catalysts for steam reforming are based on
nickel and are much sensitive to sulfur contaminating the catalyst at
contents of 0.1 ppm of sulfur or higher. Other catalysts based on iron
oxides (Fe3O4), based on chrome oxides (Cr2O3), based
on copper oxides and chrome and zinc oxides over alumina are also used in
these scale reactions. Hydrogen production systems (as disclosed below
and electrolytic processes) are very expensive in technical and energetic
resources. Thermal and electrical energies as required for the existing
hydrogen production systems are supplied by means known as
"thermoelectric external means". These treatment processes and systems
depend on the external supply of process energies.

[0006] They are also industrial systems producing high negative impact
over the environment, especially concerning the "carbon" impact due to
CO2 rejects imputable to the consumed energies and to the process
itself.

[0007] An object of the present invention is to avoid the inconveniences
as mentioned above.

[0008] Another object of the present invention is to propose a process and
a system to produce hydrogen with less power consumption.

[0009] Another object of the invention is to propose an autonomous
production system for hydrogen, releasing the hydrogen production system
from the dependence on continued external supplies.

[0010] Another object of the invention is to propose a hydrogen production
system and process with low impact over the environment.

[0011] The invention enables to reach the above mentioned objects by means
of a process to produce hydrogen from dry raw material, said process
comprising at least one iteration of the following steps:

[0012] gasification in a first so-called gasification reactor of dry
material containing carbon with a gaseous flow of gasification containing
CO2 at high temperature and oxygen, said gasification supplying a
first gaseous flow essentially containing molecules of carbon monoxide
(CO) and eventually di-hydrogen (H2) molecules, as well as
eventually water steam (H2Osteam);

[0013] oxidation, in a second so-called oxidation reactor, by oxygen
holders in oxidized state (MeO) and a gaseous flow containing oxygen,
said molecules of carbon monoxide (CO) and di-hydrogen molecules
(H2) present in said first gaseous flow, said oxidation supplying a
second gaseous flow at high temperature containing CO2, oxygen
holders in reduced state (Me) and eventually water steam
(H2Osteam) proportionally to hydrogen contained in the chemical
formulation of said dry raw material containing carbon;

[0014] activation within a third so-called activation reactor of said
holders of oxygen in reduced state with a gaseous flow of activation
essentially containing water steam, said activation supplying holders of
oxygen in oxidized state, a third gaseous flow containing di-hydrogen
(H2) and an excess of thermal power.

[0015] The essential part of the gasification of the dry material
containing carbon in the first reactor is performed as long as said dry
material containing carbon includes (in its chemical composition)
molecular oxygen or not, in two distinct and simultaneous steps.

[0017] the pyrolytic action firstly occurs in the core of the material, by
means of intense thermal supply, by the heating gas essentially
comprising CO2. Such pyrolysis decomposes molecules of said dry raw
material containing carbon (MPCS) and makes the primary gasification of
molecular carbon by composition between the C and the molecular oxygen
1/2O2 to obtain CO. Said decomposition releases (eventual) molecular
hydrogen from the chemical composition of the material, and carbons not
having their equivalent gasification "oxygen" in matrix molecules remain.

[0018] These carbons will then react over heating CO2, which will be
reduced by capturing 1/2O2 as required to enter the gaseous phase.
This reaction converts as many CO2 molecules in CO as C molecules in
CO according to Boudouard balances at the temperature of 1000° C.

[0019] If said dry material containing carbon (MPCS) does not have other
molecular oxygens in its chemical composition, gasification occurs in one
single step:

[0020] initially, the increase in the temperature of said dry material
containing carbon (MPCS) by intense thermal supply to the core of the
material by the heating gas essentially comprising CO2, so that (as
long as said temperature reaches the reaction plateau from 500° C.
until the conclusion at 1000° C.) carbons react with the heater as
per Boudouard balances. Said reaction converts (reduces) to CO a CO2
molecule exchanging an atom of oxygen with an atom of carbon (C) of said
dry raw material containing carbon, to gasify that organic and/or
amorphous carbon into CO with no external supply of pure oxygen.

[0021] The raw material containing carbon may be any material containing a
carbon rate which can be explored in its chemical composition. The yield
of the process is relative to the rate of that element by unit of matter,
as well as the hydrogen content of its composition.

[0022] The process of the invention no longer requires a continued power
supply from an external source of power. The only external power as
consumed by the process of the invention is the eventual thermal power
required to start the gasification step in the start of the process. Once
the gasification is started, the process of the invention generates
sufficient thermal power (which is mostly recovered by the active flows
of the process of the invention) to perform the set of steps of the
process and the global operation of the system.

[0023] Therefore, as we will detail below in the description, the
available power for the thermal capacity of the second gaseous flow (and
eventually by complementing the thermal power as generated by the forced
oxidation of a part of the dry raw material containing carbon), as well
as by the excess of thermal power as supplied: by oxidation of the
synthesis gas (from the gasification of said dry raw material containing
carbon) in the second so-called oxidation reactor and by activating the
oxygen holders MeO (by reducing H2O in H2), is sufficient to
supply the thermal treatment system with thermal power, is sufficient to
bring the gaseous flow of gasification to the gasification temperature
and is sufficient to produce the water steam as required for the desired
production of hydrogen, so to perform a new gasification step and,
therefore, a new iteration of the steps of the process.

[0024] Therefore, the invention allows the production of hydrogen from
carbon-containing raw material, more specifically biomass, with higher
yielding than the processes and system of the current state of the art,
with no negative impact for the environment and, in this case, notably
less than other known systems and processes.

[0025] The process of the invention can advantageously comprise the use of
thermal power from said second gaseous flow and/or said thermal excess of
said activation by the production of at least one part of said gaseous
flow of activation from water.

[0026] Therefore, after the starting cycle, the process of the invention
does not require an external power supply.

[0027] Advantageously, the process of the invention can, on the other
hand, comprise a recovery of at least one part of the CO2 as present
in the second gaseous flow to compose, at least in part, the gaseous flow
of gasification for the next cycle.

[0028] Therefore, the process of the invention allows to recycle the
produced CO2 and reduce negative impacts over the environment.

[0029] On the other hand, at least a part of the water steam as present in
the second gaseous flow may be condensed and recovered to compose at
least a part of the gaseous flow of activation.

[0030] Therefore, after the starting cycle, the process of the invention
recycles the water coming from the molecular hydrogen component of the
raw material to reduce its need for external water, as required for the
production of hydrogen.

[0031] On the other hand, the process of the invention may comprise a
temperature increase in the gaseous flow of gasification, with at least
one part of the thermal excess of activation of oxygen holders and a part
of the thermal power as generated during gasification to bring said
gaseous flow of gasification to the gasification temperature for the next
cycle.

[0032] All the energy required for that temperature increase can be
eventually obtained with the thermal complementation as supplied by an
oxygen (O2) supply in the gasification reactor. This supply, on the
other hand, is limited to the desired thermal requirements, each molecule
of O2 oxidizes two molecules of hydrogen (H2) and/or atoms of C
to make two H2O and/or two CO (or one and another as a function of
the initial composition of raw material containing carbon), thus
generating the thermal power as useful for the reactions of the process
of the invention. Besides the thermal complement supplied to the process
of the invention, each CO allows to generate a molecule of pure hydrogen
(H2).

[0033] In a very advantageous version, the process of the invention may
comprise the recycling by photosynthesis of a part of the CO2 as
present in the second gaseous flow in a microalga culture bioreactor,
said bioreactor supplying, on one hand, a gaseous oxygen flow (O2)
and, on the other hand, the carbon-containing biomass.

[0034] Therefore, the process of the invention allows to recycle the
excess of CO2 as produced by the reactions, in a photosynthetic
reactor consuming the carbon and releasing the oxygen from the molecule.
Therefore, in this advantageous version, the process of the invention no
longer depends on a source of O2 as required for any oxycombustion.

[0035] The only oxygen consumed by the process of the invention is the
oxygen eventually required to start the gasification step early in the
process and the oxygen for thermal complementation as required for the
process.

[0036] In fact, at least a part of the gaseous flow of oxygen (O2)
may be used in the gasification reactor to gasify the raw material
containing carbon. That oxygen then substitutes the one coming from
external sources, thus reducing the economic and environmental impact of
the process of the invention.

[0037] On the other hand, the process of the invention may comprise the
recovery of at least one part of the biomass containing carbon to be
gasified in the gasification reactor. Therefore, the process of the
invention allows the production of at least a part of the biomass as
consumed in the gasification reactor.

[0038] Another object of the invention proposes a system to produce
hydrogen from raw material containing carbon, said system comprising:

[0039] a gasification reactor for raw material containing carbon with a
gaseous flow of gasification containing CO2 at high temperature and
the supply of oxygen (O2) allowing an eventual thermal
complementation useful for the gasification reactions; said gasification
reactor supplies a first gaseous flow essentially containing carbon
monoxide (CO) molecules and di-hydrogen (H2) molecules (molecular
hydrogen contained in the chemical formulation of said dry raw material
containing carbon).

[0040] a reactor for oxidation by oxygen holders in oxidized state (MeO)
of said molecules of carbon monoxide (CO) and said molecules of
di-hydrogen (H2) as present in said first gaseous flow, said
oxidation reactor supplying a second gaseous flow at high temperature
containing CO2 and water steam (H2Og), oxygen holders in
reduced state (Me) and an excess of thermal water;

[0041] an activation reactor for said oxygen holders in reduced state with
a gaseous flow of activation essentially containing water steam, said
activation reactor supplying holders of oxygen in oxidized state and a
third gaseous flow containing di-hydrogen (H2) and an excess of
thermal power.

[0042] On the other hand, the system of the invention may contain at least
one thermal exchanger supplying at least a part of said gaseous flow of
activation and at least a part of the thermal power of said second
gaseous flow and/or said thermal excess of said activation.

[0043] Advantageously, the system of the invention can, on the other hand,
contain a recycling circuit for at least a part of the CO2 as
present in the second gaseous flow to compose, at least in part, the
gaseous flow of gasification for the next cycle.

[0044] On the other hand, the system of the invention can also comprise
the recovery of at least a part of the water steam as present in the
second gaseous flow to compose at least a part of the gaseous flow of
activation.

[0045] In an advantageous version, the system of the invention may also
comprise a microalga culture bioreactor to recycle by photosynthesis a
part of the CO2 as present in the second gaseous flow, said bioreactor
supplying, on one hand, a gaseous oxygen flow (O2) and, on the other
hand, carbon-containing biomass.

[0046] Finally, the system of the invention may comprise:

[0047] a recovery circuit for at least one part of the gaseous flow of
oxygen (O2) for injection in the gasification reactor to gasify the
raw material containing carbon; and/or

[0048] a recovery circuit for at least a part of the biomass containing
carbon for gasification in the gasification reactor.

[0049] Oxygen holders may contain NiO, Fe2O3, MgO, CaO, etc.

[0050] Other advantages and characteristics will appear from the analysis
of the detailed description of a non-limitative way of embodiment and the
attached figures:

[0051] FIG. 1 is a schematic representation of a first version of a system
of the invention; and

[0052] FIG. 2 is a schematic representation of a second version of a
system of the invention.

[0053] In the examples, the dry material containing carbon MPCS, taken as
a reference, is plant biomass. Reactions, energy transfers and
thermochemical conversions are identical, no matter which is the MPCS,
and only the quantitative result in produced hydrogen depends on the rate
of carbon and molecular hydrogen as contained in the chemical composition
of said MPCS.

[0054] According to an example of embodiment, the load of dry material
containing carbon may contain:

[0055] plant or animal biomass;

[0056] coal;

[0057] peat;

[0058] lignite;

[0059] organic or non organic residues;

[0060] worn tyres; or

[0061] any combination of these carbon-containing materials.

[0062] Generally speaking, organic biomasses contain hydrogen in their
molecular composition. The chemical composition of said biomasses is (in
average) 50% of C, 44% of O2 and 6% of H2.

[0063] However, we have also found hydrogen in certain coals or other
sources of amorphous carbon, as well as in certain residues containing
carbon, which may be used as dry material containing carbon MPCS.

[0064] FIG. 1 is a schematic representation of a first version of a system
of the invention.

[0065] The system 100 shown on FIG. 1 contains a gasification reactor 102,
an oxidation reactor 104 and an activation reactor for oxygen holders
106.

[0066] The dry raw materials containing carbon MPCS are introduced in the
gasification reactor 102 and subsequently flow by gravity into that
reactor by means of a tubular net serving as grids (not shown) which
reduce the speed of that flow.

[0067] A gaseous flow of gasification FGG essentially composed by reactive
CO2 and heating CO2 under a temperature of 1000° C. is
introduced in the gasification reactor 102 and eventually enriched by
pure oxygen (O2) (this supply of oxygen (O2) eventually allows
useful thermal complementation to the gasification reactors, temperature
maintenance of the gasification reactor 102 and a thermal complementation
of the gaseous flow of gasification FGG). Said gaseous flow of
gasification FGG is injected in said gasification reactor in counter
current from the flow of carbon-containing materials MPCS.

[0068] CO2 as introduced finds the raw material containing carbon
MPCS which, in this stage, has reached a temperature ≧1000°
C. This pyrolytic action cracks the molecules of the dry material
containing carbon MPCS. At the conversion/pyrolysis temperature of
1000/1100° C., the molecular cracking of the dry material
containing carbon MPCS is athermal. The primary reaction of the meeting
between the dry material containing carbon MPCS and the gaseous flow of
gasification FGG is the pyrolysis/gasification of said MPCS, during which
C and O of the molecular composition are combined into CO (primary phase
of carbon gasification). Simultaneously, CO2 conversion into CO
(i.e. in thermal power) over each element of C not having equivalent
molecular O is generated. This pyrolytic action is applied to every dry
material containing carbon MPCS which chemical composition includes
carbon and molecular oxygen. In cases where said raw material containing
carbon MPCS does not contain molecular oxygen, the conversion reaction
between 500° C. and 1000/1100° C. is performed.

[0069] Eventually, a thermal complement can be generated in the center of
the gasification reaction by the introduction of oxygen (O2) in the
gaseous flow of gasification FGG. Each mole of this oxygen as introduced
then oxidizes two moles of H2 and/or two moles of C, generating the
corresponding thermal power in the core of the gasification reactor. Said
eventual complement allows to control the thermal regulation of the
reactions in said gasification reactor and increase the yield of the
reactions so to increase the final production of hydrogen.

[0070] According to the chemical properties of said dry material
containing carbon MPCS, the result of said conversion/pyrolysis will have
different composition:

[0071] if said material containing carbon is an amorphous coal which
content of carbon is ≧80% and does not contain elements of
molecular oxygen or hydrogen, the reaction in said gasification reactor
102 will be the conversion of CO2 in CO over the carbons of said dry
raw material containing carbon MPCS;

[0072] if said raw material containing carbon is an organic biomass and/or
a mixture of materials and residues, which chemical composition comprises
elements of molecular oxygen and elements of molecular hydrogen, the
result of the reaction in said reactor 102 will be the gasification of
said dry raw material containing carbon MPCS. That reaction is firstly a
pyrolysis, alongside which the dry raw material containing carbon MPCS is
molecularly cracked; firstly, carbons are gasified by their reaction with
molecular oxygen and the release of molecular hydrogen (H2).
Subsequently, CO2 is converted into CO over the carbons of said dry
material containing carbon MPCS which do not have its equivalent in
molecular oxygen to be gasified. CO2 forecasted for this effect
therefore supply 1/2O2 to C to gasify them under the CO form, which
are themselves converted into CO, thus in new energy. These CO, with the
molecules of hydrogen (H2), transfer the full power potential of the
dry raw materials containing carbon MPCS to the following reactive
sectors in the system 100.

[0073] Therefore, the result of the reactions differs, in said
gasification reactor 102, as a function of the quality of the dry raw
material containing carbon MPCS. The following demonstration takes as an
example raw material organic biomass which average chemical composition
is:

[0074] 50% carbon: 500 grams 41.667 mol of C

[0075] 44% oxygen: 440 grams 13.750 moles of O2

[0076] 6% hydrogen: 60 grams 29.762 moles of H2

[0077] Cracking/Combination Action:

[0078] The dissociation of the raw material containing carbon MPCS,
combination of C in CO and the release of H2 is athermal (at the
conversion/pyrolysis temperature of 1000/1100° C. of the process
of the invention) and only the specific heat of said dry material
containing carbon MPCS should be supplied by the gaseous flow of
gasification FGG to obtain reactions.

[0079] Conversion Reaction:

[0080] From CO2 to CO is endothermal, according to the reactions:

CO2-1/2O2=CO+O+283 kJ/mol

C+1/2O2 (from CO2)=CO-111 kJ/mol

[0081] i.e. a thermal deficit of 172 kJ/mol of CO2.

[0082] Each one of the two molecules of CO as obtained has a heating power
of 283 kJ/mol, i.e. a total 566 kJ, while the heating power of C
(material containing carbon source of the primary reaction energy) is 394
kJ/mol. Under these conditions, the main object is to supply 172 kJ from
the conversion endotherm by means not imputable to this power potential
or by external thermal means by introducing another power which would
compromise such yield. The molecular cracking of dry raw material
containing carbon MPCS and the consequent gasification is athermal at the
conversion/pyrolysis temperature of 1000/1100° C.; therefore, the
hydrogen released during said cracking therefore does not need specific
thermal supply, but at a power potential of 242 kJ/mol.

[0083] On the other hand, to increase the temperature of said dry material
containing carbon MPCS and the gaseous flow of gasification FGG, "heat"
thermal power is required and should be supplied by said gaseous flow of
gasification FGG (complemented, be it the case, by the thermal power as
generated by H2 and/or C oxidation by oxygen O2 as brought to
the pyrolysis means, with said gaseous flow of gasification FGG, to
produce useful thermal capacity).

[0084] In this example of organic materials, "biomass" as dry raw material
containing carbon MPCS: for the "primary" gasification phase, each mole
of C will react with 1/2 mol of O2 coming from the molecular
composition to generate one mole of CO; considering 27.5 moles of CO for
13.750 moles of O2 (which are able to oxidize 27.5 moles of C into
CO).

[0085] At the end of that "primary" gasification reaction, we will have:

[0086] 27.5 moles of CO;

[0087] 29.762 moles de H2;

[0088] 14.17 moles of C which do not have its equivalent O in the chemical
formulation of dry material containing carbon MPCS.

[0089] To gasify these 14.17 moles of C, 1/2 mole of O2 is required,
therefore, as much CO2, i.e. 14.17 moles which will be converted
into CO to exchange 1/2 mole of O2 to 14.17 moles of C, thus giving
28.34 moles of CO.

[0096] The required energy to take the kg of MCPS at 1100° C. is:
1,068.210 kJ; to take 14.17 moles of CO2 (as required to conversion)
at 1100° C., 717.930 kJ are required; to compensate the endotherm
of the conversion of 14.17 moles of CO2, 2,437.24 kJ are required.

[0098] To supply this process power, the gaseous flow of gasification FGG
(which is composed, in the case of this example, of 14.17 moles of the
third gaseous flow of recycled CO2 TFG1 coming from the reactor 106)
can be heated: by an external thermal process, using a part of the
synthesis gases of the process of the invention; or by an external system
using any source of energy as per the skills known by the experts in the
art. In the start of the process of the invention, the system will be
brought to the required temperature for the beginning of reactions by one
of these means (not shown). These will subsequently supply thermal power
and the reactive and heating gas useful to subsequent reactions.

[0099] In a pyrolytic means of the invention, molecular hydrogen reacts
first with the available oxygen. The process of the invention (in this
specific case) has 29.762 moles of H2, with a heating power (once
oxidized by the oxygen as injected with the gaseous flow of gasification
FGG) of 242 kJ/mol for a total energy of: 7,202.404 kJ.

[0100] To obtain and/or collect the thermal capacity as required to the
reactions in the gasification reactor 102, said third gaseous flow of
recycled CO2 TGF1 coming from the reactor 106 (to be transformed in
the gaseous flow of gasification FGG, once acquired at the useful thermal
capacity) circulates in a tubular network of thermal exchange. Said third
gaseous flow TFG1 recovers, during this path, at least a part of the
available thermal energies (generated during the reaction chain in the
system), and thus acquiring a part of useful thermal capacity.

[0101] If said third gaseous flow TFG1 is composed of just 14.17 moles of
CO2 useful to the conversion reaction, during its transit in the
exchanger 108, it is at a temperature of more than 800° C., i.e. a
thermal capacity recovered of only: 574.334 kJ.

[0102] Therefore, 4,233.38-574.344=3,649.036 kJ of thermal capacity are
missing for the reactions in the gasification reactor 102.

[0103] As we will see in the demonstration sequence, the power is
available (as generated by the reaction chain) to supply such thermal
capacity. This induces the transport of that energy from the source to
the gasification reactor 102. For that, a complement of recycled CO2
is required (an external supply is then useful to start the process).

[0104] To generate such thermal power, an injection of O2 can be
effected with a gaseous flow of gasification FGG at its inlet in reactive
phase in the gasification reactor 102.

[0105] In the pyrolytic means of the invention at 1100° C.,
molecular hydrogen reacts initially with the available oxygen and the
process of the invention (in this case) has 29.762 moles of H2, with
total heating power of: 7,202.404 kJ.

[0106] If this is the chosen option, 15.079 moles of hydrogen are required
to produce the missing thermal capacity. Each injected mole of O2
will react with two moles of hydrogen to produce two moles of H2O
and 7.54 moles of O2 are then required to compensate the lack of
thermal capacity useful for this reaction. 14.683 moles of H2 will
remain to be reacted with CO to perform the sequence of the reactions
leading to the production of pure hydrogen.

[0107] The third gaseous flow TFG1, circulating in the tubular network
(performing the role of exchanger and grids to reduce the speed of flow
of the oxidizing/deoxidizing materials) located in the reactions of
oxidation 104 and reactivation 106 and the thermal exchanger 108,
acquires its whole useful thermal capacity and becomes the gaseous flow
of gasification FGG. It is at the reaction temperature of that
pyrolysis/conversion chamber ≦1100° C. in which it is
injected with the 7.54 moles of O2 required for the reactions.

[0108] In this specific case, at the outlet of the gasification reactor
102, a first gaseous flow PFG is obtained (per kg of dry raw material
containing carbon MPCS biomass), composed by 55.84 moles of CO+14.683
moles of H2 and 15.079 moles of water steam (H2Og) at a
temperature of more than 900° C. This first gaseous flow PFG is
therefore eminently full of power and reactive. It allows power transfer
from carbon-containing raw materials to the oxidation reactor 104, with
no dissipation or losses. It is then introduced in the oxidation reactor
104, where it will be oxidized by the contact of oxygen holder materials
MeO in active or oxidized state.

[0109] The active oxygen holders MeO are introduced in the oxidation
reactor 104 at the level of an upper part of that reactor 104 and flow
through tubular grids performing a role of thermal exchanger and grids
(not shown) decelerating this flow.

[0110] Said first gaseous flow PFG coming from the gasification reactor
102 is essentially composed (as per the reference example: for 1 kg of
dry raw material containing carbon (MPCS) of 55.84 moles of CO+14.683
moles of H2+15.079 moles of water steam (H2Og). It is at a
temperature of more than 900° C. when introduced in the oxidation
reactor 104 (at the level of a lower part of that reactor 104) in counter
current to the flow of oxygen holders MeO. The meeting between oxygen
holders in oxidized state MeO (or active) and the first gaseous flow
causes:

[0112] the oxidation of 14.683 moles of hydrogen H2 in water steam
(H2Og); this reaction is exothermal and releases 242 kJ/mol;
i.e. 3,553.286 kJ (these 14.683 moles of water steam are added to the
15.079 moles generated by the production of thermal requirements of the
gaseous flow of gasification FGG for the total 29.762 moles
(H2Og) present in the raw material containing carbon MPCS
biomass);

[0113] to perform said oxidations, 70.253 moles of MeO are required; the
reduction of said 70.253 moles of MeO, active oxygen holders, is
endothermal and absorbs 244.3 kJ/mol, i.e.: 17,228.669 kJ.

[0115] Therefore, the oxidation reactor 104 is exothermal for 2,127.239 kJ
per kg of MPCS biomass, thus more than 90% (≈2,000 kJ) are
recovered by the third recycled gaseous flow TFG1 and the balance is
recovered in the exchanger 108.

[0116] Said oxidation reactor 104 supplies a second gaseous flow DFG at
high temperature (≧900° C.) essentially comprising CO2
and H2O and oxygen holders Me in reduced state (deactivated).

[0117] The oxidation reactor 104 is kept at a correct temperature level
(≦1000° C.) thanks to the tubular net working as a thermal
exchanger and grids, wherein the third recycled gaseous flow TFG1
circulates, exiting the activation reactor 106 where it will collect its
essential thermal capacity, at the same time regulating the temperature
of said oxidation reactor 104.

[0118] Therefore, this second gaseous flow DFG has an important thermal
power: 3,573.083 kJ of thermal capacity+2,228.951 kJ from enthalpy of the
29.762 moles (H2Og) condensed in liquid H2O, i.e.:
5,802.034 kJ. That thermal power is used in a thermal exchanger 108 to
generate a gaseous flow of activation FA essentially containing water
steam from liquid water.

[0119] This second gaseous flow DFG at the outlet of the thermal exchanger
108 is cold (at the temperature of the liquid water as injected in the
exchanger to produce the gaseous flow of activation FA). The water steam
as present in this flow is condensed and separate from the CO2
existing in that flow.

[0120] At the outlet of the thermal exchanger, we will then have:

[0121] liquid water (condensed) 29.762 mol

[0122] a gaseous flow of activation FA essentially comprising water steam,
70.523 moles of H2Og at a temperature of 800° C. and
pressure of approximately 0.3 MPa; [0123] latent heat (vaporization at
800° C.) of said gaseous flow of activation FA is 5,281.645 kJ
which will be provided by the thermal exchanger 108 over 5,802.034 kJ
available at the outlet of the oxidation reactor 104; there are still
available: 520.389 kJ per kg of MPCS biomass;

[0124] a third gaseous flow TFG of CO2 at high temperature and dry.

[0125] We will see below in the disclosure that these three products will
be at least partly used in the system 100.

[0126] Oxygen holders Me in reduced state are introduced into the
activation reactor 106. The transference of oxygen holders from the
oxidation reactor 104 to the activation reactor 106 is performed by
mechanical means 110. This transference can also be performed by gravity
following the configuration of these two reactors.

[0127] Deactivated oxygen holders Me are still at high temperature of
about 800° C. and are eminently reactive. In this activation
reactor 106, oxygen holders in deactivated state Me are reactivated by
the oxygen of the gaseous flow of activation FA, which is essentially
composed of water steam H2O circulating counter curent; 70.523 moles
of Me react with 70.523 moles of H2O to produce 70.523 moles of
H2, 142.174 grams of pure hydrogen per kg of MPCS biomass which
higher heating power (PCS) is ×242: 17,066.566 kJ.

[0128] The oxidation of oxygen holders Me in contact with water steam
produces, on one hand, active oxygen holders MeO and, on the other hand,
a gaseous flow of di-hydrogen FGH.

[0129] While the gaseous flow of activation FA is solely composed by water
steam, the gaseous flow of hydrogen FGH is composed of pure hydrogen.

[0130] The final reaction (III) verified in that activation reactor 106 is
exothermal and has an excess of energy according to the balance:

[0131] The activation reactor 106 is then exothermal of 162.203 kJ per kg
of MCPS biomass which, added to the specific heat of the gaseous flow of
hydrogen FGH (thermal capacity), are recovered by the third recycled
gaseous flow TFG1 in the exchanger incorporated in said activation
reactor 106. Said thermal capacity of said gaseous flow of hydrogen FGH
at 800° C. is, for the 70.523 moles of H2: 2,054.523 kJ; i.e.
a total 2,216.726 kJ.

[0132] This thermal capacity is exchanged in the third recycled gaseous
flow TFG1 to effect pre-heating and especially to enable the temperature
reduction of the hydrogen as produced (per kg of dry raw material
containing carbon PCS) at room temperature.

[0137] The reacted oxygen holders in MeO are transferred to the oxidation
reactor 104 by mechanical means 110.

[0138] A part TFG1 of the third gaseous flow TFG exiting the exchanger 108
and essentially composed of CO2 is recycled and used as a gaseous
flow of gasification for the following cycle. The other part TFG2 of the
second gaseous flow is stocked or rejected in the atmosphere.

[0139] However, this gaseous flow TFG1 is cold and should be heated for
use as a gaseous flow of gasification FGG.

[0140] This gaseous flow TFG1 passes for one first time through the
tubular net of the activation reactor 106, wherein it lowers the
temperature of the gaseous flow of hydrogen FGH (which is composed by
pure hydrogen) and where it acquires thermal capacity. It subsequently
circulates in the dedicated tubular net of the thermal exchanger 108,
located at the outlet of the activation reactor 106 to acquire a second
part of its thermal capacity (at a temperature higher than 800°
C.) thanks to the thermal excess of the oxidation reactor 520.389 kJ
added to 2,216.726 kJ of the activation reactor 106, i.e. 2,737.115 kJ.
From that thermal excess, only 717.930 kJ are consumed by 14.17 moles of
reactive CO2 of the gaseous flow TFG1, 2,019.185 kJ are then
available for the reaction chain of the process of the invention. This
thermal excess is used to optimize various power transferences to the
different reactions. It will be advantageously used in substitution to
the thermal supply useful to the gasification reaction as supplied by the
oxidation of molecular hydrogen by injected O2. That substitution
will allow to offer molecular hydrogen molecules for the chain reaction
in the oxidation 104 and activation 106 reactors to produce the
equivalent in process supplement H2.

[0141] At the outlet of the activation reactor 106 and the thermal
exchanger 108, a gaseous flow of CO2 is obtained at a temperature of
more than 800° C. To raise the temperature of that gaseous flow of
CO2 and obtain a gaseous flow of gasification FGG which temperature
is 1000° C. or higher, the flow TFG1 passes through a thermal
exchanger located in the oxidation reactor 104 where it acquires all its
thermal capacity useful for the conversion over the materials containing
carbon. The gaseous flow of gasification FGG as obtained at the outlet of
that exchanger is then injected into the gasification reactor to gasify
the dry raw material containing carbon from the next cycle.

[0142] The liquid water as obtained at the outlet of the exchanger 108 may
be used to generate gaseous flow of activation FA for the following
cycle.

[0143] The global remaining power is balanced and the excess of thermal
power as generated along the reaction chain compensates various wastes
and consumptions of the system/process of the invention.

[0144] When the process/system of the invention is started, it may be
advantageously optimized by recycling the energies as generated in the
reaction chain. Such optimized thermal recovery is made by using
complementary heating CO2, which function is to collect its thermal
capacity in the non-used excess and take that thermal capacity to the
core of the dry raw material containing carbon. Therefore, such
optimization of non-used power recovery reduces the needs of oxygen
supply and saves the equivalent amount in molecular hydrogen molecule
oxidation (for the production of reaction energy). These molecules of
hydrogen are therefore saved to produce moles which can be oxidized by
complementary MeO producing moles of pure hydrogen at the end.

[0145] FIG. 2 is a schematic representation of a second way of embodiment
of a system of the invention.

[0146] The system 200 represented by FIG. 2 comprises all the elements of
the system 100 as represented by FIG. 1.

[0147] The system 200 also contains a bioreactor 202 containing
microalgae.

[0148] The portion TFG2 of the third refrigerated gaseous flow TFG
obtained at the outlet of the exchanger 108 is injected into the
bioreactor 202. In the alga culture bioreactor 202, carbon dioxide
CO2 is used by photosynthesis as performed by microalgae.
Photosynthesis produces, on one hand, the biomass containing carbon BC
and, on the other hand, a gaseous flow of oxygen FO2 by separating
the carbon element "C" from the molecule of dioxygen "O2".

[0149] The biomass containing carbon BC as obtained is supplied to a
biomass conditioning system 204 which may be e.g. a drying system for
said biomass containing carbon BC to be conditioned before its
introduction in the gasification reactor 102.

[0150] The gaseous oxygen flow FO2 may be supplied to the system of
the invention, e.g. at the level of the gasification reactor 102 to be
substituted with the oxygen used to complement thermal power useful for
the gasification of carbon-containing material in the reactor 102.

[0151] Advantageously, the production of carbon-containing biomass in this
second way of embodiment stimulates the global yield of the facility by:

[0153] a biomass coal (pyrolysis residue of extraction of the molecules
with high added value), partly feeding up the process of the invention
with dry material containing carbon;

[0154] full recycling of the CO2 flow TFG2, closing the gaseous
circuit of the process of the invention.

[0155] Said production of carbon-containing biomass can also be fully
introduced in the system/process of the invention. Thus, the circuit of
raw material containing carbon is also made in closed ring and the
hydrogen is continually produced with minimum impact over the environment
and its resources.

[0156] In this example, carbon is oxidized by the molecule of O2,
thus again generating a CO2 which is recycled in the same fashion.
There are no atmospheric emissions or CO2 sequestration to be
organized.

[0157] Therefore, the process and system of the invention are independent
from any external source of energy after the starting stage.

[0158] The invention is surely not limited to the examples as disclosed
above.